If you are not an Apple-dominated household, the chances are that any network-based sharing of media in your home is based on DLNA. In my office, for example, I can just mirror the screen of my Android phone to my LG TV using DLNA. Or I can use an app on my Android tablet to send music, which is residing on my 8TB of Network Attached Storage, to a network streamer attached to my audio system. Likewise, video and photos on the NAS to the TV.
Increasingly these days your music “media” is in digital storage – on hard disk or flash memory, or even the cloud – and there are a proliferation of ways in which the music is delivered to a playback device.
The most common way to handle all that is through protocols developed by the Digital Living Network Alliance, or DLNA.
What is it
DLNA has two meanings. One is the actual organisation, the “Alliance” behind it. This was started by Sony and Intel in the early 2000s “to develop and promote a set of interoperability guidelines for sharing digital media among multimedia devices under the auspices of a certification standard”. In other words, they saw how consumer entertainment technology and computer technology were converging, and they wanted to come up with standards so that all the different parts of the media system could work well with the other parts.
The goal: to make it easy for the regular person at home.
It seems the Alliance did its job quite well. Four years ago it declared victory, packed up its bags and went home. The Alliance was formally dissolved and certifications palmed off to a firm that specialises in providing certification services.
These days we tend to use the terms DLNA and uPnP – Universal Plug and Play – interchangeably. So, for example, the app I use on the Android tablet I mentioned above to manage my DLNA music is called BubbleUPnP. uPnP is not actually a very good name. It isn’t universal, and PnP has other meanings in the computing context. In reality, though, DLNA is in large part a subset of uPnP, with restrictions designed to keep things easier for consumers.
And, of course, not all non-Apple media connection standards are DLNA/uPnP. For example, Chromecast uses different protocols. And, indeed, last time I checked, Google Pixel phones don’t natively support DLNA/uPnP at all. (A word of warning there. You might want your next TV to be Android-based if you use a Pixel.)
From here on out, I’ll be using DLNA to refer to the products using those standards, not the organisation. Note that some brands use other names for DLNA. LG, for example, calls it “Smart Share”. Samsung calls it “All Share”.
DLNA supports music, video and still photo streaming. But not all devices are required to support all three. I will just be talking about music here.
Servers and players and renderers
Conceptually a DLNA system is divided up into four parts, although some of the parts might be physically located in the same device.
First, there’s the Digital Media Server. A server has two jobs: it stores your music, and it also “serves” it up to the network. The storage side of things is obvious, but the serving thing is less so. Your music is just a collection of files. The server software examines each file and creates indexes based on such things as album, artist, genre, possibly composer and various other things. This is based on the identifying metadata tags in the music files (so it’s worthwhile to have a consistent tagging system for your music).
Any Windows computer from recent years is a DMS. These typically have the DLNA server function switched on by default. Earlier ones used Windows Media Player for that service. Network Attached Storage isn’t a DMS necessarily, but most models comes with DMS software. I run two different sets of software – MinimServer and Media Server on my Synology NAS because they have different and complementary capabilities. An Android tablet or phone also acts as a DMS for any music in its storage.
Next, we have two functions which are related, but subtly different: the Digital Media Player and the Digital Media Renderer. The Renderer is the engine that turns the digital data into actual music: it “renders” the music, in the same way that a graphics program “renders” a final image. A DMP includes a DMR, but it also adds all the necessary stuff to actually make use of the music. It reads the lists of artists and whatnot served up by the DMS and presents them to you, the user, for you to choose the music to be played.
The DMP was for quite a few years the main way that one would interact with DLNA content. Your home theatre or stereo network receiver would have an input setting called “Network”. From that you’d select “Media Server” or some such, then choose “Music”, then drill down through the lists presented. How effective all this was depended a great deal on whether your receiver’s remote had a way of jumping you quickly through long lists to find the items that you wanted to play. When you selected a song, the receiver would “render” it into music.
But a DMR can exist independently of a DMP. Nowadays the standard way to use DLNA is to employ a DMC to send music from the DMS to the DMR. Let me explain!
The DMC is a Digital Media Controller. In just about all cases, this is software on a tablet or phone: iOS or Android. It talks to both the DMS and the DMR. It reads the lists served up by a DMS and presents them to you to choose what you want to hear. When you make a selection the DMC tells the DMS to send the digital music to the DMR, and hence it plays.
The point of this is two-fold. First, the digital audio streams directly from server to renderer, not through the tablet or phone. So if your music is high resolution FLAC or DSD, there won’t be WiFi bottlenecks (at least between your phone and your other devices). Second, you have a greater choice of controllers.
These days most good gear capable of streaming network audio supports DMP and DMR functions, and also has available an app which acts as a DMC. Mostly, but not always, the app is locked to that brand (or other brands in the same family). The Denon Hi-Fi Remote app won’t stream music to my Cabasse Stream Source. However the Awox Cabasse Stream Control DMC will stream to the Denon DNP-730AE network streamer. But there are lots of third party DMCs as well. I generally like to use BubbleUPnP on Android for this purpose because it populates long lists quickly and allows me a degree of control not provided by many other apps. If, however, you’re using an iPad or iPhone, there aren’t many third party DMCs, so you may be stuck with the proprietary app.
One important consideration with DLNA devices is whether they support gapless playback. Music files are computer data. Computer data is always organised in blocks at some level or other. These bock boundaries usually don’t align precisely with the end of a musical track. So, in playing back an album where each track merges into the next without a pause, you may find yourself experiencing irritating brief pauses between each track.
Gapless playback is a feature in which such pauses are eliminated so that the music flows smoothly from track to track. However, for this to work it has to be supported by the music itself, by the server, by the player and by the renderer. In general FLAC is capable of being rendered gaplessly, along with iTunes-style AAC, and MP3 encoded using iTunes or the LAME encoder.
My Synology NAS’s Media Server software originally did not support gapless playback, and after one of its occasional updates it suddenly did. The Denon DNP-730AE network media player does, but the previous model (DNP-720AE) reportedly only provided partial support. It would support gapless playback when used as a Digital Media Player (that is, when it was pulling music from the server), but not when being used as a Digital Media Renderer (that is, a controller was being used to push music to it from the server). My Denon streamer is five years old now. Virtually all streamers I’ve tested in recent years support gapless playback, although I usually have to switch this one for the particular renderer in BubbleUPnP.
If you find all this confusing, don’t consider yourself alone. There are an enormous number of combinations in which any single weak link can stop gapless playback. If you’re buying, have the store demonstrate that whichever device you are purchasing is, in fact, gapless. Test with an album with run-on music, preferably in FLAC format, so that you can check. If it’s a player, make sure that it is gapless not only with its own internal interface (ie. it’s acting as a DMP), but also when music is pushed to it by a Digital Media Controller.
All this might make it seem hard. But it’s worth it. I have all my music sitting on a NAS, able to be dialled up in an instant and delivered at full resolution using a tablet as a controller. No switching of discs. If an album is coming towards the end, I can enqueue another before the currently playing content comes to an end. My several-hundred CDs are still in place on the shelves, but I rarely bring them down. And the NAS also has lots of high resolution content drawn from DVD Audio and Blu-ray.
We do live in wondrous times for the music lover.